The loading condition of a vehicle may be measured by various techniques and methodologies. For example, vehicle-mounted tires may be equipped with strain sensors that detect and measure the deflection of each tire from tire loading. By measuring tire deflection, and thereby the vehicle's loading condition (full, half-full, empty), systems such as stability/brake/traction control systems may be adjusted as a function of the loading condition. Of particular importance is the determination of loading in off-road vehicles such as mining trucks that may operate under full or partial loaded conditions during normal operation. While measuring vehicle loading through evaluation of tire deformation is an effective technique, factors that affect tire deformation such as road condition, sensor dependability, and operating conditions (i.e. inflation pressure, temperature, aging) can make the accuracy of a tire-deflection determination problematic. It is accordingly desirable to be able to estimate a vehicle's load condition by indirect measurement of the vehicle loading condition, independently of any tire-mounted load sensor. A suitable indirect methodology and system would preferably use commonly available vehicle measured parameters in order to minimize the cost and complexity of load estimation system integration.